"We are stuck between a rock and a hard place. It is a lose-lose situation," she said.

Mrs McCarnun and her husband make sure that their four children eat first, and then pick on the leftovers, she told BBC News. They have both lost weight and been ill as a result.

Food parcels from the Trussell Trust are designed to last three days, but they eke them out to last a week.

It is not just homeless people using the food banks she explains, "it is working families that are finding it hard. It is is going to spread and it is going to get worse".

She is the full-time carer for one of her children, five-year-old Rowan, who is disabled.

"Trying to explain to Rowan that you can't provide - he doesn't understand that.

"When he asks for something, we can't provide it and he doesn't understand. And that is heartbreaking," she said.

'More need and awareness'

The Trussell Trust released its statistics to coincide with World Food Day.

The trust runs a network of 270 food banks across the UK, staffed by volunteers with food products donated by local people.

The charity is launching a new food bank in the UK every three days and expects this growth to continue until 2015.

Adrian Curtis, food bank network director for the trust, said the increase in numbers using UK food banks reflected a rise in food and utility bills, people losing their jobs and having less disposable income, and greater awareness that food banks exist.

"It's a combination of more need and more awareness," he said.

"We're seeing more and more people on a low income using a food bank," he added.

"They're not necessarily people who are welfare dependent. They're working families but can't afford to buy their way out of hard times."